76 
Magazine  of  the  School  of  Agriculture. 
appreciable  extent.  In  Upper  India,  in  the  well- 
watered  provinces  of  the  Punjab  and  the  Gangetic 
plain,  ‘ singhara  ’ is  a well-known  cry  in  the 
vegetable  markets.  There  are  more  than  one 
species  which  produce  the  spinous  fruit.  The 
large  seeds  of  the  Trapa  bicornis,  a native  of 
China,  so  called  because  of  its  two  recurved  and 
obtuse  horns,  and  of  the  Trapa  bispinosa  and 
Trapa  natans,  species  indigenous  to  India,  are 
sweet  and  eatable.  Dr.  Royle  writes  that  the 
‘ singhara  ’ forms  a considerable  portion  of  the 
food  of  the  inhabitants  of  Kashmere,  and  we  learn 
from  Mr.  Forester  that  they  yielded  the  Govern- 
ment £12,000  a year  of  revenue.  Mooreroft 
mentions  nearly  the  same  sum  as  Maharaja  Runjeet 
Singh’s  share,  from  96,000  to  128,000  ass-loads 
of  this  nut  being  yielded  by  the  Wulur  Lake 
alone.  In  the  Punjab  the  variety  known  as 
singhara  purbeya,  or  eastern  or  down  country 
water  caltrop,  such  as  that  found  in  the  pools 
about  Jullunder  cantonment,  is  deemed  of  superior 
quality.  The  nut  abounds  in  fecula,  and  in 
China  the  kernel  is  popularly  used  as  an  article 
of  food,  being  roasted  or  boiled  like  the  potato. 
“ Even  as  an  ornamental  plant  the  two-horned 
Trapa  is  not  without  its  merits.  The  long  stalks 
of  the  plants  reach  up  to  the  surface  of  the 
water,  upon  which  their  green  leaves  gracefully 
float,  whilst  their  pure  white  flowers  expand 
beautifully  among  them  in  the  sheen  of  an  Indian 
afternoon  in  the  monsoon.  The  nut  itself  grows 
under  water  after  the  flower  decays : it  is  of 
triangular  shape  and  covered  with  a tough  brown 
integument  adhering  strongly  to  the  kernel,  which 
is  white  and  esculent  and  of  a fine  cartilaginous 
texture.  It  ripens  in  the  latter  end  of  the  rainy 
weather,  and,  in  the  N.-W.  P.  at  least,  is  eatable 
till  November.  In  these  Provinces  the  cultiva- 
tion of  the  two-spined  water  caltrop  is  extensively 
carried  on  by  the  Dbimar  castes  who  are  every- 
where fishermen  and  y/a/Ah-bearers,  keeping  boats 
for  planting,  weeding,  and  tending  his  water 
crop.  The  holdings  of  each  cultivator  are  marked 
out  in  the  tank  by  bamboos,  and  they  pay  so 
much  an  acre  for  the  portion  they  tend.  The 
rent  paid  for  an  ordinary  tank  is  about  R100 
a year,  but  R200  or  R300  are  ordinarily  paid 
for  a large  tank.  The  plants,  however,  are  said  to 
cause  such  an  increase  of  mud  that  a tank  is  quickly 
spoiled  by  them,  and  the  cultivation  is  not  allowed 
where  the  tank  is  required  for  a water  reservoir.” 
This  last  statement  would  seem  to  prove  that 
the  Trapas  are  not  so  suitable  for  growth  as 
checks  to  evaporation.  The  Agricultural  Gazette 
of  N.  S.  Wales  referring  to  checking  of  water 
evaporation  by  means  of  aquatic  plants  dis- 
tinguishes T.  bicornis,  T,  bispinosa,  and  T.  natans. 
as  ling  nut,  singhara  nut,  and  water-chesnut 
respectively,  and  notes  that  their  fruits  are  of 
considerable  size,  abound  in  farinaceous  matter, 
and  are  of  considerable  economic  value,  and  goes 
on  to  observe  that  “they  are  admirably  adapted 
for  growing  in  Australian  waters  which  are  not 
impregnated  with  any  mineral  constituent  delete- 
rious to  plant  growth.  . . .”  The  absorption  by 
their  roots,  which  are  as  fine  as  hair,  from  J 
to  3 inches  long,  and  the  transpiration  of  their 
leaves,  which  are  spread  over  the  surface  of  the 
water  very  quickly,  are  exceedingly  small  in 
connection  with  the  beneficial  check  these  plants 
have  on  the  evaporation  of  water. 
GRAFTING  MANGOES  AND  ORANGES. 
“ W.  A.  D.  S.”  writes  from  Bombay  : — “ Since  last 
I wrote  to  you  about  the  grafting  of  mangoes,  I 
have  observed  more  of  the  processes.  Besides 
grafting  young  plants  on  to  trees,  what  is  known 
as  “ side-grafting  ” is  practised.  Two  or  three 
incisions  are  made  in  the  trunk  of  a tree,  and 
small  twigs,  about  i an  inch  in  thickness,  from 
a good  variety,  are  grafted  on  to  the  trunk  by 
cutting  their  ends  wedge-shaped.  These  wedges 
are  fitted  to  the  incisions  made  in  the  stem, 
and  are  set  with  a little  bees-wax,  any  space 
left  between  the  wedge  and  the  tree  being 
padded  with  cotton.  The  whole  is  then  rubbed 
over  with  clay  and  cowdung,  and  after  covering 
with  a piece  of  plantain  stalk  is  tightly  bound 
round  with  a single  string  of  ccir-yarn  wound 
over  the  whole  surface.  The  process  is  considered 
easy  and  generally  produces  the  desired  result.” 
It  will  be  remembered  that  the  first  process 
of  grafting  described  by  “IF.  A.  D.  S.”  was  that 
known  as  “ inarching,”  or  grafting  by  approach, 
which  two  other  correspondents  referred  to  as 
being  practised  in  the  Northern  Province. 
In  his  Primer  of  Agriculture,  Mr.  H.  W.  Green 
describes  the  methods  of  cleft-grafting,  saddle- 
grafting,  side-grafting  and  splice-grafting. 
Dr.  Nicholls,  in  his  book  on  “ Tropical  Agri- 
culture,” thus  refers  to  the  method  known 
as  “ crown-grafting  ” which  he  says  is  very 
useful  in  orange  culture,  especially  when  it 
is  desired  to  graft  sweet  oranges  on  to  a 
large  and  old  sour  orange  stock.  The  trunk 
of  the  tree  is  cut  right  through  with  a saw, 
and  then  smoothed  off  with  a knife.  Two  or 
three  scions  are  then  inserted  between  the  bark 
and  the  wood.  It  will  be  found  much  easier 
to  insert  the  scions  if  a piece  of  hard  wood 
cut  the  exact  size  and  shape  of  their  ends  be 
used  to  force  a passage  between  the  bark  and 
the  wood  of  the  stock.  Grafting  by  approach 
or  inarching  is  also  extensively  employed  in  the 
West  Indies  for  the  multiplication  of  the  plants 
of  the  better  kinds  of  mangoes. 
The  following  are  the  advantages  of  budding 
and  grafting : — Many  delicate  plants,  and  more 
especially  fruit  trees  are  rendered  much  hardier 
by  their  branches  being  made  to  grow  on  strong 
stocks,  and  when  they  become  hardier  they 
naturally  give  a larger  return  in  fruit.  Besides, 
some  plants  which  are  very  difficult  to  propagate 
by  cuttings  are  easily  multiplied  by  budding  and 
grafting,  and  seedling  fruit  trees,  -which  take  a 
very  long  time  to  bear  can  be  made  to  fruit 
much  earlier  by  these  processes.  In  the  case, 
too,  of  oranges  and  other  fruit  trees,  the  seeds 
do  not  always  produce  plants  that  bear  fruit  of 
the  same  character  as  that  of  the  parents — in 
fact  they  do  not  “ breed  true.”  That  is  to  say, 
if  the  seed  of  a very  fine  orange  be  planted, 
the  fruit  obtained  from  the  seedling,  when  it 
has  grown  to  a tree,  may  after  all  be  of  a 
worthless,  character ; so  that  after  the  trouble 
of  nursing  the  tree  from  the  seed,  and  after 
weary  waiting  for  years  for  the  produce,  nothing 
but  disappointment  may  be  the  result.  But  by 
adopting  the  < system  of  budding  or  grafting,  the 
fruit  could  be  harvested  in  a much  shorter  time, 
with,  the' certainty  that  all  the  characteristics, 
of:  the  original  plant  would  be  preserved. 
